User interface for supplying gases to an airway

ABSTRACT

A user interface convertible between a nasal configuration and an oral configuration. The user interface has a nasal cannula and a mouthpiece. The nasal cannula has a body portion and at least one prong extending from the body portion, the prong being adapted to direct a flow of gas into a nare of a user&#39;s nose. The mouthpiece is adapted to engage the mouth of the patient and direct a flow of gas into a user&#39;s mouth. In the nasal configuration the prong of the nasal cannula is adapted to direct a flow of gases into a nare of the patient. In the oral configuration, the nasal cannula is engaged with the mouthpiece such that a gases flow is provided to at least the mouth of the user.

TECHNICAL FIELD

The present disclosure relates to user interfaces for medical circuitsfor conveying gases to and/or from a user.

BACKGROUND ART

Patients may lose respiratory function during anaesthesia, or sedation,or more generally during certain medical procedures. Prior to a medicalprocedure a patient may be pre-oxygenated by a medical professional toprovide a reservoir of oxygen saturation, and this pre-oxygenation isgenerally carried out with a bag and a face mask. Once under generalanaesthesia, patients must be intubated to ventilate the patient. Insome cases, intubation is completed in 30 to 60 seconds, but in othercases, particularly if the patient's airway is difficult to traverse(for example, due to cancer, severe injury, obesity or spasm of the neckmuscles), intubation will take significantly longer. Whilepre-oxygenation provides a buffer against declines in oxygen saturation,for long intubation procedures, it is necessary to interrupt theintubation process and reapply the face mask to increase the patient'soxygen saturation to adequate levels. The interruption of the intubationprocess may happen several times for difficult intubation processes,which is time consuming and puts the patient at severe health risk.After approximately three attempts at intubation the medical procedurewill be abandoned.

In this specification where reference has been made to patentspecifications, other external documents, or other sources ofinformation, this is generally for the purpose of providing a contextfor discussing the features of the disclosure. Unless specificallystated otherwise, reference to such external documents is not to beconstrued as an admission that such documents, or such sources ofinformation, in any jurisdiction, are prior art, or form part of thecommon general knowledge in the art.

SUMMARY

It is an object of the present disclosure to provide an interface thatwill at least go some way towards improving on the above or which willat least provide the public and the medical profession with a usefulchoice.

The interface system may be configured to deliver general anaesthetic tothe user via the aperture or the port of the user interface, whileseparately or in addition, also to deliver a high flow of oxygen to thenares of the user via the nasal cannula.

Other drugs or agents or medicaments or gases delivery is alsocontemplated. Anesthesia delivery is one example provided in thisspecification to give context to the present interface system, and itwill be appreciated other delivery of medicament/drugs or gases can beprovided through the systems and devices disclosed herein.

In accordance with at least one of the embodiments disclosed herein is apatient interface comprising a combination of an oro-nasal mask and anasal cannula assembly, each of said mask and nasal cannula assemblyprovided with separate gas flow supply from one or more sources, saidnasal cannula being independently locatable upon a user from said mask.

In accordance with an aspect of the invention, there is provided a userinterface convertible between a nasal configuration and an oralconfiguration, the user interface comprising: a nasal cannula having abody portion, at least one prong extending from the body portion, theprong being adapted to direct a flow of gas into a nare of a user'snose, a mouthpiece adapted to engage the mouth of the patient and directa flow of gas into a user's mouth, in the nasal configuration the prongof the nasal cannula is adapted to direct a flow of gases into a nare ofthe patient, and in the oral configuration, the nasal cannula is engagedwith the mouthpiece such that a gases flow is provided to at least themouth of the user.

The user interface may be further convertible into an oro-nasalconfiguration.

The user interface may further comprise a gas delivery conduit, and avalve between the nasal cannula and the mouthpiece, wherein in the nasalconfiguration, the gas delivery conduit delivers a flow of gas to thenasal cannula and the valve prevents or substantially inhibits a flow ofgas between the nasal cannula and the mouthpiece, in the oralconfiguration, the gas delivery conduit delivers a flow of gas to themouthpiece and the valve prevents or substantially inhibits a flow ofgas between the nasal cannula and the mouthpiece, and in the oro-nasalconfiguration, the gas delivery conduit delivers a flow of gas to themouthpiece or the nasal cannula and the valve allows a flow of gasbetween the nasal cannula and the mouthpiece.

The mouthpiece may be clipable onto the cannula.

The gas delivery conduit may be attachable to either the nasal cannulaor to the mouthpiece, and the gas delivery conduit is moveable betweenthe nasal cannula and the mouthpiece.

The valve may be or comprise a flap valve that seals either the nasalcannula or the mouthpiece from the other of the mouthpiece or nasalcannula that is receiving flow from the gas delivery conduit.

The mouthpiece may comprise an opening adapted to receive and allowinstruments to be inserted through the mouthpiece, the mouthpiecefurther comprising a valve or seal to seal around the mouthpieceopening.

The mouthpiece may be adapted to surround at least a portion of thecannula and the mouth piece has an outer periphery that substantiallyconforms to the area of a patient's mouth, such that in use at least aportion of the mouth is at least partially occluded.

The mouth piece may be slidable relative to the cannula.

In the oral configuration the mouthpiece may be insertable into themouth of the user such that the at least one prong of the nasal cannulaprovide a gases flow to the mouth of the patient.

The mouthpiece may be inflatable such that the mouthpiece at leastpartially occludes or at least partially seals with the mouth of theuser.

The mouthpiece may comprise an inflatable cuff, the cuff adapted toconform to the shape of the mouth to create a seal with the mouth.

The prongs may be configured to at least partially occlude or at leastpartially seal with the user's nares, in use.

The prongs may be inflatable.

The mouthpiece may comprise an extended section that is adapted toextend into the airway of the patient and lie over the top of the tongueof the user.

In accordance with an aspect of the invention, there is provided a userinterface for providing a flow of respiratory gases to a patient duringa medical procedure comprising a nasal interface comprising a body and apair of prongs extending from the body, the prongs configured to engagenares of the patient's nose and direct high flow respiratory gases intothe nares a mouthpiece adapted to engage the mouth of the patient; andwherein the prongs and/or the mouthpiece are configured to at leastpartially occlude either an oral airway, a nasal passage, or both theoral airway or nasal passage in use.

The user interface may be configured to create at least a partial sealwith the nares of the patient.

The user interface may be configured to create at least a partial sealwith the mouth/oral airway of the user.

The user interface may be adapted to allow a user to selectively createat least a partial occlusion with the nares of the user/patient or withthe oral airway/mouth or with both.

The user interface may be shaped to create a seal with the nares of theuser.

The user interface may be shaped to create a seal with the user's mouthor oral airways.

The user interface may be arranged to direct high flow respiratory gasesinto the mouth/oral airways of the patient.

The user interface may be inflatable to create at least a partial sealwith the nares of the patient.

The mouthpiece may be inflatable to create at least a partial seal withthe mouth of the patient.

The user interface may further comprise a mechanical control mechanismthat allows selective inflation of the prongs, the mouth piece, or boththe prongs and the mouthpiece.

Each prong may be independently inflatable to create at least a partialseal with the nares of the patient.

Nasal interface may be removably connectable to the mouthpiece.

The mouthpiece may be inflatable when the nasal interface is connectedto the mouthpiece.

The mouthpiece may comprise a passage to allow insertion of a medicalinstrument through the mouthpiece, the mouthpiece may be shaped toconform to the shape of a patient's mouth to create a seal with themouth.

The passage is selectively openable and closeable to seal around themedical instrument inserted through the mouthpiece.

The passage may comprise a passage inflatable seal, the passageinflatable seal being adapted to seal around a medical instrumentinserted into the passage.

The mouthpiece may comprise an outer inflatable seal that is adapted toinflate to create a seal with the mouth of the patient.

The user interface may further comprise a seal activation mechanismcontrolling the inflation and deflation of the prongs and/or themouthpiece.

The user interface may further comprise a valve that can be selectivelyopened or closed based on the patient's inspiration and expiration.

The mouthpiece may comprise a pressure line, the pressure line includesa cover slip that is moveable within the pressure line, the movement ofthe cover slip controlling opening and closing of the valve, the coverslip configured to move to open the valve during inspiration and thecover slip configured to move to close the valve during expiration.

In accordance with an aspect of the invention, there is provided amouthpiece for use in medical procedures comprising: a body, the bodyincluding an opening to allow insertion of a medical instrument andbeing configured to create a seal with the mouth of the patient toincrease pressure in the airways of the patient.

The mouthpiece may further comprise an inflatable cuff disposed on thebody of the mouthpiece, the inflatable cuff creating a seal with thepatient's mouth when inflated.

The mouthpiece may comprise an opening seal for sealing around theopening to retain the medical instrument.

The user interface may be a bite-block having a passage which can beselectively opened or closed.

Disclosed is a patient interface comprising at least one deliveryelement for delivering or directing a flow of supplied gas to a nare orthe nares of a user's nose, wherein each delivery element comprises ofat least one lumen through which said flow of supplied gas is directed,and wherein the flow of supplied gas is modified according to one ormore forms is provided within or about an interior of one or more ofsaid at least one lumen.

Said form may be a, or one more, surface relief portions or regionsprovided as part of an internal wall surface of one or more of said atleast one lumen.

Said form may be a projection extending radially inwardly from or alongan interior wall surface of one or more of said at least one lumen.

Said form may be a depression or recess provided within or along aportion or region of an interior wall surface of one or more of said atleast one lumen.

Said form may extend in a continuous or discontinuous manner along orabout the delivery element, from a downstream location to a moreupstream location, said location being relative to the direction of theflow of suppled gas through said delivery element.

Said form may comprise one or more partitions extending along a lengthand/or across a cross-sectional area of the at least one lumen of a saiddelivery element.

Said form may be one or more partitions arranged or arrayed in one or acombination of the following:

-   -   substantially concentric configurations, each of said partitions        defining at least a part of a further one of said at least one        lumen, whether said partitions define a lumen that extends        substantially the entirety of the length, or a partial length,        of the total length of a delivery element through which said        flow of supplied gas is directed,    -   a hexagonal or honey-comb type configuration of partitions,        whether said partitions defines at least a part of a further one        of said at least one lumen, or whether said partitions define a        lumen that extends substantially the entirety of the length, or        a partial length, of the total length of a delivery element        through which said flow of supplied gas is directed,    -   a cross-hatch or grid-type arrangement of partitions when viewed        as a cross-section through the gas delivery element, the        cross-section being taken as a substantially orthogonal plane        relative to the direction of the flow supplied gas through the        gas delivery element,    -   a plurality of intersecting partitions providing plurality of        divisions or dividing interior walls within at least one of said        lumen of said delivery element,    -   a plurality of intersecting partitions providing for a plurality        of separate gas flow pathways within at least one of said lumen        of a said delivery element,    -   one or more partitions are vanes interposed within one or more        lumen of said delivery element,    -   combinations of one or more of the above arrangements or arrays.

Said form may be one or more partitions, a partition being a dividingwall or structure extending through or across a delivery element for gasflow modification or gas flow re-direction.

Said form may impose upon the flow of gas through one or more regions ofone or more delivery elements.

Said form may impose upon the flow of gas through one or more regions ofone or more delivery elements to modify the gas flow by reducing orincreasing the Reynolds number of the flow of gas, or at least portionsof the flow of gas, through one or more regions of the delivery element.

Said form may impose upon the flow of gas to increase, or decrease, thekinetic energy of a bulk of the gas flow through the delivery element,or a localised or partial portion of the gas flow through the deliveryelement.

Said form may comprise a helical structure or surface relief extendingfrom, or imposed upon, an interior wall portion of said at least onelumen of one or more gas delivery elements.

Said form may comprise striations.

Said striations may be oriented along or with or against a flowdirection of supplied gas through a gas delivery element.

One or more of said form(s) may be located in one or more of:

-   -   in a portion or region closer to an outlet from the delivery        element than an inlet of the supplied gases to the delivery        element,    -   in a portion or region closer to an inlet to the delivery        element than an outlet of the supplied gases from the delivery        element,    -   in a portion or region comparatively more downstream than an        upstream portion or region of a delivery element relative the        flow of gas supplied,    -   in a portion or region comparatively more upstream than a        downstream portion or region of a delivery element relative the        flow of gas supplied,    -   at or substantially adjacent to an outlet (or an end) from the        delivery element of the supplied gases,    -   an outlet end of the delivery element,    -   an outlet end of said delivery element may comprise the form as        one or a serried of serrated surfaces or undulating shaped or        castellated edge portions.

Said form may be one or more ribs provided substantially longitudinallyaligned with a gas flow direction through the delivery element, or saidone or more ribs is/are provided substantially laterally (or anotherorientation) substantially relative to a gas flow direction through thedelivery element.

Said form may be of a regular or irregular geometry, when viewed as across-sectional profile or as plan view of a surface of a deliveryelement including such a said form or forms.

The, or one or more of said, form(s) may be gas flow directors.

A said form may straighten or direct the gas flow into a flow pathtrajectory or other gas flow characteristic.

Said form may straighten said gas flow or provides or alters said gasflow as a jet or focused flow of gas through or from said deliveryelement or through or from at least one of said lumen through a deliveryelement.

Said form may operate as a gas flow multiplier for increasing theflowrate of provided to a user, the gas flowrate provided to a userbeing greater than the total gas flowrate delivered through the deliveryelement of a said interface.

Said delivery element may be oriented or angled, such that in-use, saiddelivery element may be oriented or angled toward a user's septum.

Said delivery element may extend to, or substantially adjacent to,in-use, one of:

-   -   a user's nasal valve    -   the velopharynx    -   sufficiently deep into a user's airway or nasal cavity, so s to        in-use, avoid or by-pass gas flow being provided in contact with        a user's relatively sensitive nasal epithelia.

A delivery element may extend in flow path length, whether automaticallyin response to a characteristic of the supplied gas or by manuallyactuation.

Said delivery element may be telescopic.

Said delivery element responds to a change in temperature or a change inhumidity or an electrical current applied thereto.

Said response may be an alteration or change in the geometry or flowpath of a said delivery element.

An outlet from a delivery element may be shaped or configured to changethe velocity of gas exiting said delivery element.

Said velocity (whether as a bulk property or a localised property ofsaid supplied gas passing through or exiting a said delivery element)may be increased or decreased.

Said form may be a flow restrictor.

Said delivery element may be of a non-sealing type relative to an airwayor a nasal cavity or nare into which said delivery element is to belocated, optionally such that the nare or airway that said deliveryelement may be to be located within does not occlude the entire airwayor a nare when in-situ.

Said delivery element may further comprise one or more structurespositioned on an exterior surface of said delivery element, such that,in-use, said a sealing of said delivery element with an airway or a narewhen in-use, is dissuaded or avoided or prevented.

Said delivery element may be of a sealing-type, optionally wherein thedelivery element occludes or seals the airway or nare when in-situ.

Said delivery element may further comprise one or more structurespositioned on an exterior surface of said delivery element, such that,in-use, said a sealing of said delivery element with an airway or a narewhen in-use, is encouraged.

Said structure(s) may comprise one or more inflatable members forencouraging of said sealing, optionally said member being at least oneinflatable cuff.

The inflatable member may be inflated to a pressure proportional to thepressure of the supplied gas or to a pressure correlated to the pressureof the supplied gas.

Said inflatable member may be inflated by the supplied gas.

Said inflatable member may be inflated by a source of gas other than thesupplied gas.

The inflatable member may be manually inflated by a user, or may beautomatically inflated, such as in response to a supplied source of gas.

Said delivery element may further comprise an accommodation to allow forinsertion of an instrument or tube or conduit or other airway equipment,including a bougie, into a said delivery element to access a user'sairway, such as a nasal cavity or nare.

Said delivery element may be a nasal prong.

Said interface may be a nasal cannula including one or a pair of nasalprongs.

In some configurations, there is provided as a nasal cannula comprisingone or a pair of nasal prongs as said delivery elements, in combinationwith a further patient interface when provided as an oro-nasal orfull-face type mask, optionally each of said patient interfaces suppliedseparately with a source of gas to their gas outlet from respectivedelivery elements.

The or an interface or a component associated with a system forproviding a supply of gas to said interface, may include a pressurerelief mechanism.

The pressure relief mechanism may be a valve or other seal configured toopen once a pre-determined pressure is experienced or sensed within adelivery element or at a location along a gas flow path of the gassupplied to the interface or a said gas delivery element, or saidpre-determined pressure is measured or sensed at another locationexternal to the interface of the system for providing the supply of gas.

It is an object of certain embodiments disclosed herein to provide animproved patient interface or systems or devices associated with patientinterfaces that might solve one or more of the above problems, or atleast provide the public with a useful choice.

As relatively high gas delivery flow rates may be used with theembodiments or configurations described herein, the gases being suppliedor delivered to the user or patient may be delivered to different partsof the user's or a patient's airway. The gases being supplied may reachthe patient's lungs or any part of the respiratory system.

For example, according to those various embodiments and configurationsdescribed herein, a flow rate of gases supplied or provided to aninterface or via a system, such as through a flow path, may comprise,but is not limited to, flows of at least about 5, 10, 20, 30, 40, 50,60, 70, 80, 90, 100, 110, 120, 130, 140, or 150 liters per min (LPM), ormore, and useful ranges may be selected between any of these values (forexample, about 40 to about 80, about 50 to about 80, about 60 to about80, about 70 to about 80 LPM). Optionally, the gases supplied may bedelivered in a fully saturated or humidified condition, or a saturatedor humidified gas may be blended with other gases for supply or deliveryto a patient interface or the patient.

Such relatively high flow rates of gases may assist in providing thesupplied gases into a user's airway, or to different parts of a user'sairway, for example such flow rates may allow for a delivery of suchgases to the upper or lower airway regions. Upper airway regiontypically includes the nasal cavity, pharynx and larynx, while the lowerairway region typically includes the trachea, primary bronchi and lungs.

Each of the various configurations or embodiments or configurationsdescribed herein may be utilised in combination with one or more of theother various systems, devices (including interfaces) or methods alsodescribed herein.

The term “comprising” as used in this specification means “consisting atleast in part of”. When interpreting each statement in thisspecification that includes the term “comprising”, features other thanthat or those prefaced by the term may also be present. Related termssuch as “comprise” and “comprises” are to be interpreted in the samemanner.

To those skilled in the art to which the invention relates, many changesin construction and widely differing embodiments and applications of theinvention will suggest themselves without departing from the scope ofthe invention as defined in the appended claims. The disclosures and thedescriptions herein are purely illustrative and are not intended to bein any sense limiting. Where specific integers are mentioned hereinwhich have known equivalents in the art to which this invention relates,such known equivalents are deemed to be incorporated herein as ifindividually set forth.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the disclosure will be described by way ofexample only and with reference to the drawings, in which:

FIGS. 1a and 1b show configurations having manually sealable port on thecannula.

FIGS. 2a and 2b show configurations having a sealable port on the mask.

FIGS. 3a to 3d show another configuration, in the form of a modular,adaptable interface that has two parts: a nasal cannula and a mouthinsert.

FIGS. 4a to 4f show another configuration, in the form of a modular,adaptable interface that has two parts: a nasal cannula and a mouthinsert.

FIGS. 5a and 5b show another configuration, in the form of a modular,adaptable interface that has two parts: a nasal cannula and a mouthinsert.

FIGS. 6a to 6c shows another configuration, having breath-controlledsealing between the nasal cannula and the mouth insert.

FIGS. 7a to 7c shows another configuration, in which a mask and cannulaare used together.

FIGS. 8a to 8h , show configurations that allow the user interface to beconvertible between a nasal cannula configuration and an oralconfiguration.

With respect to each of FIG. 9A parts (a), (b) and (c)—these showvariations of a delivery element that includes a form to be imposed upona gas flow through the lumen of the delivery element.

With respect to each of FIG. 9B parts (a), (b) and (c)—these showfurther variations of a delivery element that includes a form to beimposed upon a gas flow flowing through a delivery element.

FIGS. 10A (a) and (b) show different views of a delivery element inwhich a honey-comb-like arrangement of forms are provided within thelumen of a delivery element.

FIG. 10B shows a delivery element with a grid-like or mesh-likearrangement of forms.

FIG. 10C shows a delivery element including an array of concentricallyarranged forms, including additional forms for dividing or partitioningof the delivery element.

FIG. 11 shows a configuration in which multiple delivery elementsprovided in an airway, such as a pair of nasal prongs provided in asingle nostril, and may be orientated.

FIG. 12 shows a configuration of a delivery element in which wallsections of a nasal prong may be subject to ballooning when underpressure from the gas flowing therethrough, or the walls may berelatively thin to allow for such change in shape of the deliveryelement.

FIG. 13 shows a general patient interface, with a pair of deliveryelements as nasal prongs including inflatable members as inflatablecuffs about the exterior surface of the delivery element.

FIGS. 14A and 14B show a first embodiment of a user interface whichcomprises a selectively activated seal.

FIGS. 15A and 15B show a second embodiment of a user interface whichcomprises a selectively activated seal.

FIGS. 16A and 16B show another embodiment of a user interface whichcomprises a selectively activated seal.

FIG. 17 shows an alternative embodiment for increasing occlusion of theuser interface.

FIGS. 18 and 19 show an alternative embodiment for increasing occlusionof the user interface.

FIG. 20 shows an alternative embodiment for increasing occlusion of theuser interface.

FIG. 21 shows an alternative embodiment for increasing occlusion of theuser interface.

FIG. 22 shows a typical airway of a person, and includes arrows toindicate how a relatively high flow rate of gases supplied to a user maybe utilised to effectively push or drive the supplied gases further ordeeper into a user's airway than when the person is under normal ortypical self-driven respiratory conditions.

DETAILED DESCRIPTION OF THE DRAWINGS

In the field of medical circuits, and in particular breathing circuitsfor delivering general anaesthetics to users via gases or vapours,maintaining users' physiology at safe levels, namely oxygen, CO₂ andanaesthetic drugs is a major concern. Before a user receivesanaesthetics via breathable gases, it is critical that a user isprovided a sufficient amount of oxygen to flush out the CO₂ and the N₂in the user's body during the pre-oxygenation phase, before anaestheticscan be applied.

Atelectasis is the collapse or closure of alveoli in the lungs resultingin reduced or absent gas exchange (ventilation) and occurs inapproximately 90% of anaesthetised patients. It occurs both duringspontaneous breathing and after muscle paralysis and regardless ofwhether intravenous or inhalation anaesthetics are used.

The atelectatic lung area can exceed 20%, and in the case of thoracicsurgery more than 50% of the lung can collapse.

In addition to atelectasis, airway closure during anaesthesia alsocauses reduced ventilation and together can account for as much as 74%of impaired arterial oxygenation.

Application of about 10 cmH2O PEEP (positive end expiratory pressure)has been shown to re-open atelectatic lung regions and prevent airwaycollapse, however, it is thought this is more likely an effect ofincreased inspiratory and expiratory airway pressures rather than PEEPitself.

The current disclosure is directed to systems and apparatus that providepressure for example PEEP or inspiration pressure and may at leastprovide 10 cmH2O PEEP to maintain open alveoli.

Atelectasis can remain for several hours after surgery and lung collapsereoccurs rapidly after discontinuation of PEEP.

The provision of a relatively high flow rate of gases to a user orpatient can in some configurations be employed to deliver elevatedairway pressures during anaesthetic pre-oxygenation, apnoeicoxygenation, and recovery. It will be appreciated that such a therapy ofdelivery of such a therapy to a user patient may be used in situationsother than just during procedures utilising anaesthetics.

As relatively high gas delivery flow rates may be used with theembodiments or configurations described herein, the gases being suppliedor delivered to the user or patient can may be delivered to differentparts of the user's or a patient's airway.

Such relatively high flowrates of gases may assist in providing thesupplied gases into a user's airway, or to different parts of a user'sairway, for example such flowrates may allow for a delivery of suchgases to the upper, middle or lower airway regions. The embodimentsdescribed here provide partial occlusion of the patient's airways, whichis advantageous because it prevents atelectasis and prevents alveolicollapse while still providing the benefits of high flow delivery.

A unique ability to maintain elevated airway pressures using suchrelatively high flowrates in an uninterrupted manner means pre-, duringand post-surgery atelectasis and airway closure can be minimised andventilation (i.e. gas exchange in the lungs) is maintained. For example,in this context “ventilation” does not mean artificial ventilationthrough a ventilator machine. The embodiments described here provide amodular interface that allows a clinician or user to customize aninterface such that therapy delivery can be maintained, or remainsubstantially uninterrupted even if one airway is in use and cannot havean interface applied to it.

The various disclosed configurations and embodiments herein provide fordevices, systems and methods for enhancing an ability to deliveryelevated airway pressures and do so without interruption for a user orpatient.

Patient interfaces, such as full-face masks (including oro-nasal masks)and nasal cannula or nasal pillows or nasal plugs or nasal maskstypically provide for a particular delivery of gases for administrationor provision of a desired gas therapy to a user or wearer of theinterface.

Clinicians may wish to vary the flow of gas that is delivered to thepatient, for example over the breath cycle, to control the variation ofthe delivered pressure. Currently, flow delivery to the patient can onlybe controlled at the gas source. Conventional cannula designs areunsealed interfaces that use a flow-based respiratory support. This canmake it difficult to control the pressure delivered to the patient.

In some instances, there may be a desire for a user to be provided withmultiple therapies or the capability for such therapies which wouldotherwise be delivered by different patient interfaces.

There are instances in which a clinician may want to increase thepressure delivered to the patient by using an interface that at leastpartially occludes the airways of the patient. Partial occlusion allowsthe benefits of CO₂ flushing and prevent barotrauma. The partialocclusion may be fixed or variable by the clinician. Other advantages ofhigh flow delivery include oxygen delivery deeper into the patient'sairway. A patient's airway may collapse when the patient isanaesthetised.

There are also situations where a clinician will be performing aprocedure in which the patient's mouth needs to be open, for example, toinsert an instrument, and the high flow therapy and pressure of thattherapy needs to be substantially or entirely maintained. The interfacesdescribed herein allow insertion of instruments, into the patient'smouth and/or their nose, without having to remove the interface and/orstop the high flow therapy, and are able to partially occlude, partiallyseal, or seal around the inserted instruments. The interfaces mayself-seal when no instruments are inserted.

Some of the configurations described below relate to a nasal interfaceand a mask. It will be appreciated that, in-use, the mask is to beplaced over the nasal and/or oral area, preferably both the mouth andthe nose, of a user for conveying gases to and/or from the user from agases supply system (not shown) via an aperture or a port provided onthe mask. A gas conduit extends into an interior volume of the interfacealso for supplying gases to and/or from the user from a gases supplysystem (not shown). In the configurations shown and described below, theinterior volume is formed by an interior of the interface and the faceof the user, when the interface such as the mask is worn by the user.

In some configurations, the gases supply system which is in gasescommunication with the gas conduit and the interface via the aperture orthe port respectively are separate and independent of each other. In oneconfiguration, the gases supply system which is in gases communicationwith the aperture or the port of the mask is a part of an anaesthesiasystem comprises an anaesthesia machine for delivering anaesthetics tothe user, whereas the gases supply system which is in gasescommunication with the gas conduit is a high flow humidified oxygendelivery system. The nasal interface, such as a nasal cannula, may beprovided at an end of the gas conduit and within the interior volume ofinterface for providing for example a high flow of oxygen or blendedgases directly into the nares of the user.

The mask comprises a body, such as a shell. The shell may be made of anysuitable materials such as polycarbonate, plastic and similar thereof.At or adjacent the rim of the body, there is provided a seal thataccommodates the creating or forming of the seal between the interfaceand the user's face and/or a component so provided on said face. Theseal may be integrally formed with the shell such as by injectionmoulding, or it may be formed as a separate component by any suitableprocess and then attached to the shell. The seal is preferably made of asoft, flexible material to readily conform to the facial profile of auser when the interface is worn by the user to create a seal between theuser's face and the interface. Preferably the seal is a substantiallygas tight seal so the user only breathes in and/or out from the conduitor the interior volume or both.

The cannula comprises a body with a pair of prongs that extend in to thenares of the patient. The cannula is or comprises a soft material. Thecannula and prongs may be formed entirely from the soft material or mayinclude a relatively rigid portion that is overmoulded or co-mouldedwith a soft material. The cannula may include headgear such as abifurcated headgear to retain the cannula on the patient's head.

Patients that may benefit from the user interfaces described hereininclude patients with OSA (prone to collapsed airways), ARDS (stifflungs), high BMI or obstetric patients (compression atelectasis due toadditional weight on lungs. Reduced FRC), chronic obstructive pulmonarydisease (COPD) (stiff lungs), or pneumonia (atelectasis).

The configuration shown in FIG. 1a allows immediate adjustment of flowdelivery. In particular, this configuration allows manual control ofhigh flow gas delivery.

A user interface 100A has a nasal cannula 101A having a body portion103A locatable upon a face of a patient in an operational position, atleast one nasal prong 105A extending from the body portion, the nasalprong being adapted to direct a flow of gas into a nare of the patient'snose when the body portion is in the operational position. In theconfiguration shown, the user interface has two prongs 105A.

The user interface also has a port 107A located at or near the body 103Aportion, and a flow controller, in the form of a plug 109A, forselectively closing the port.

This configuration allows a clinician to watch/monitor a patient or userwhile affecting pressure to check the patient's response and adjust theflow delivery accordingly. Also, the pressure can be relieved instantlyif a risk of barotrauma is detected.

The port 107A and the plug 109A are arranged to allow at least part ofthe flow of gas to vent to control the flow of gas into the nare of thepatient's nose from the nasal prong 105A. The clinician can occlude/sealor remove the occlusion/unseal the port 107A on the cannula 101A, asdesired. Sealing or closing the port 107A means full flow is of gas isdelivered to the patient or user. Unsealing, removing the occlusion, oropening the port 107A creates pressure relief by allowing the flow tovent, as shown in FIG. 1a . If the clinician wishes deliver the flow foran extended period of time, the port 107A can be sealed with theremovable plug. The flow of gases can be varied over the breath cycle(e.g.: closed during inspiration, opened during expiration to reducepressure and risk of barotrauma, or vice versa), over a longer period oftime (e.g.: left closed for 5-10 breaths, or 30 seconds of apnoea, as alung recruitment manoeuvre), or a shorter period (e.g.: to create highfrequency oscillations/oscillatory jet ventilation)

The port 107A may be sized to vent a certain amount of flow (e.g.: vent40 lpm when run at 70 lpm). Other venting volumes are contemplated. Insome configurations the volume vented is a percentage or ratio of thetotal flow.

The port 107A may be made of an expandable material (e.g.: elasticpolymer). When greater flow is delivered, the back pressure in themanifold will be greater so the port will open wider. This may allow theflow to vent a known proportion of the delivered flow (e.g.: 50%).

An alternative configuration is shown in FIG. 1b . This configuration issimilar to the configuration shown in FIG. 1a and like numbers are usedto indicate like parts, except B is used in place of A. In thisconfiguration, the port 107B may comprise a pressure relief valve 109Bthat can be activated by a depressing a button 110B. Here the valve 109Bis naturally closed and pushing the button 110B allows flow to ventthrough the valve 109B. Alternatively, the opening could have an(adjustable) PEEP valve.

The interface 100A/100B could be used in conjunction with a sealingmouthpiece to prevent mouth leak and create a completely sealedinterface.

With reference to FIGS. 2a and 2b , another configuration of the userinterface is shown. This configuration has an oro-nasal anaesthetic mask211A placed over the nasal cannula 201A. This configuration has thenasal cannula provided with a cannula gas flow supply and the oro-nasalmask provided with a mask gas flow supply that is able to seal over thenasal cannula, in use. The mask may include a depression in the outeredge or the seal portion of the mask to allow sealing over the supplytube to the nasal cannula.

A flow controller, in the form of a cap 209A, is attached to a port 207Aof the mask 211A with an opening through it. The port 207A may belocated at or near a body portion 213A of the oro-nasal mask. The port207A and the cap 209A are arranged to allow at least part of the flow ofgas to vent to control the flow of gas into the patient's airway. Inparticular, an opening on the cap 209A can be occluded or left open tocontrol pressure delivery to patient (FIG. 2a ). Sealing the cap 209Acreates additional pressure. High flow is not able to vent to atmosphereuntil the opening is released again. Building/releasing the pressure inthe sealed interface allows manual breaths to be simulated with highflow (where releasing allows expiration). Building pressure in thepatient's airways prevents or at least substantially inhibits thepatient's airways from collapsing. This could be useful in apnoeicperiods for lung recruitment or to stimulate spontaneous breathing.

Alternatively, the flow controller could be a pressure relief valve 209Bthat can be activated by a depressing a button 210B (See FIG. 2b ). Inthis alternative, the valve 209B is naturally closed and pushing thebutton 210B allows flow to vent through the valve 209B. Alternatively,this could be an (adjustable) PEEP valve.

The mask 211A may have a self-sealing valve when the cap 209A/210B isremoved, so that if the clinician wishes to maintain pressure for a longperiod of time, they can just remove the cap. The high flow gas supplymay have a pressure relief valve to prevent hyper-inflation.

Alternatively, the mask could be connected up to a gas conduit and thecap inserted at the end of the conduit; that is, instead of a reservoirbag. If the cap is removed and replaced with a bag, this allows the userto revert to normal bag-ventilation.

There may be a pressure gauge 204A on/near the cannula or mask forvisual feedback to the user. If the mask is connected to the anaestheticmachine the pressure reading from the mask may be read off the gaugethere instead.

Methods of flow variation and port sizing described in relation to theprevious configuration also apply.

Advantages of this configuration include:

-   -   Sealed interface allows better pressure control    -   Immediate adjustment of flow delivery and/or pressure delivery        (programming a flow variation cycle in software/on the device        takes time and cannot be implemented instantly. Also any minor        adjustments require re-programming).    -   Can watch/monitor patient while adjusting pressure to respond        accordingly.    -   Measurement of delivered pressure within sealed interface.

Sometimes a clinician may wish to deliver respiratory support through anasal interface, such as during intubation attempts, sometimes they maywish to deliver respiratory support orally as the patient is a mouthbreather, or the clinicians wants to insert instruments through thenose. Sometimes it may be desirable to seal the interface to create morepressure, or have greater control over the delivered patient breath,however sometimes it may be desirable for the interface to benon-sealing to enable pressure release.

With reference to FIG. 3a , another configuration of the user interfaceis shown. In this configuration, the interface is a modular, adaptableinterface that has two parts: a nasal cannula and a mouth insert. Theparts can be attached together (eg: using mechanism as shown in FIG. 3A)or used separately, as desired. In a further alternative, they may bepermanently attached together. A gas supply conduit can be inserted intoeither part. An opening for the gas conduit may be a standard taperconnection to permit connection of most gas supply tubes. The gas may bedelivered though whichever interface the gas supply conduit is insertedinto, or the interfaces may be fluidly connected and the gas isdelivered through both interfaces. The mechanism 315A may beself-sealing such that gas does not leak out when the parts aredisconnected.

The mouthpiece 311A may be blocked with a plug 313A to maintain thepressure and prevent leak of nasally delivered high flow formouth-breathers, and prevent leak of delivered high flow through themouth. The plug 313A may contain a valve (eg: duckbill as shown in thecentre of the illustrated cap) to allow instruments to inserted whilemaintaining a seal. A duckbill valve creates a seal around theinstruments that may be inserted into the patient's mouth. After theinstrument is removed, the duckbill valve closes and maintains the seal.

FIG. 3b shows an alternative mouthpiece 311B that may have an extendedsection 317B into the airway. FIG. 3c shows another alternativemouthpiece 311C with an extended section 317C into the airway. FIG. 3dshows a further alternative mouthpiece 311D with an extended section317D into the airway. The extended section 317B/317C/317D could becurved, to lie over top of the tongue, which may be more comfortable forthe patient. The extended section 317D has an opening 318 that may alsoact as an opening to insert instruments through the nasal passages intothe airways. The shape may also help guide instruments down the airway,and the extension may help promote CO₂ flushing and O₂ delivery deeperinto the airway. A patient's airway may collapse when the patient isanaesthetised. The extended section 317B/317C/317D helps to maintain thepatient's airway open and promote gas exchange in the case of potentialcollapse. In this embodiment, there is an opening at the back of theextended section to allow gas flow from the nasal passages into thelower airways. The opening allows high flow to be delivered into thelower airways and lungs, which may not occur in some situations if highflow is delivered to nasal cavity alone. The mouthpiece may also havenasal prongs attached which may deliver high flow. The prongs may bepermanently attached to the mouthpiece (as shown in FIG. 3C) or themouthpiece may have an attachment system, such as a clip 319D or groove(as shown in FIG. 3D), that a nasal cannula may be attached to orinserted into.

With reference to FIG. 4a , another configuration of the user interfaceis shown. In this configuration, the user interface has two parts, anasal cannula 401A and a mouth insert 411. This embodiment is a modularinterface that allows a clinician or user to customize an interface suchthat therapy delivery can be maintained, or remain substantiallyuninterrupted even if one airway is in use and cannot have an interfaceapplied to it. The parts can be attached together (eg: using mechanism315A in FIG. 3A) or used separately, as desired. Alternatively, they maybe permanently attached together. The gas supply conduit 419 may beinserted into either part. If the parts are attached together, the gaswill be delivered though whichever interface the gas supply conduit 419is aligned with. The gas supply conduit 419 may be moved up and downwithin the combined interface to realign the gas entry point. Forexample see FIG. 4b : if the conduit 419 is pushed to the uppermostposition (1) (aligned with cannula), gas will be delivered through theprongs 405A. A valve will seal the flow from entering the mouthpiece.The valve may be a flap 429 that can open/close as the conduit 419pushes past. There may be rails 423 on the wall of interface opening toposition/lock the conduit 419 into place. If the conduit 419 is pushedto the lowermost position (2) (aligned with mouth), gas will bedelivered through mouth insert. If the conduit 419 is in the middle thevalve is pushed open allowing flow to be delivered to both the patient'snose and mouth.

Alternatively, it may be possible to connect more than one gas supply tothe interface, (eg: high flow through unsealed nasal prongs plusadditional pressure support through sealed oral part, or high frequencyoscillations though one part, with base flow/pressure through other).The high flow therapy may be delivered through the nasal prongs plusgases supply may be delivered through the oral part. Alternatively, highfrequency oscillations may be delivered through one part, with a baseflow or pressure through another part. In another alternative, high flowmay be delivered through the nasal prongs and the gas supply may bedelivered through the sealed oral part.

FIG. 4c shows a cross-section through a plane of the mouth insert 411,with a possible flow path to the mouth: flow comes from the gas conduit419 on the right hand side into the lower part of the interface. Theflow passes into the mouth co-axial to portion extending into the user'smouth. A co-axial flow ensures even flow distribution into the user'smouth (as opposed to flow being delivered down a channel on one side ofthe insert, into one side of the mouth)

The interface could allow connection with a standard gas conduit 419D(e.g.: FIG. 4d (1) or may use a specialised conduit connector 420 d thatengages with the interface more securely (e.g.: FIG. 4d (2)). FIG. 4d(2) shows a conduit connector that is flat or has two flat sides tofacilitate sliding up and down within the interface and the top of theconduit connector being curved with the top of the openings in theinterface, and the bottom may also be curved to correspond to the shapeof the bottom of the connector to create a seal.

The interface can be optionally partially occluded, partially sealed, orsealed, easily and immediately. FIG. 4e shows one example. The nasalprongs can be inflated to create a seal or at least a partial seal withthe one or more nostrils or nasal openings of the patient. The nasalprong may be pre-inflated and deflated by a user or clinician or may beinitially deflated and inflated by a user or clinician. Preferably thereis a partial seal in which at least above 70% of the nasal openings aresealed to create pressure but also maintain the advantages of high flowtherapy.

In some instances, the interface being sealed may be important forpatients with weak airways or obese patients. The mouthpiece beingsealed provides a seal in the patient's airways or at least a partialseal with the airways of the patient.

In other instances, the interface may not be completely sealed becausethat may cause risk of barotrauma due to excessive pressure in theairways and the interface would not then provide the benefits offlushing.

The prongs may be inflated, creating an occlusion, partial seal, or sealin the user's nares, when a lever 425E is pushed to the left, whichpushes the gas from the syringe into inflatable cuffs 427E. The partialseal may be fixed or variable by the clinician. The nasal prong may bepre-inflated and deflated by a user or clinician or may be initiallydeflated and inflated by a user or clinician. There could be twocontrols to seal each prong 405E independently (e.g.: to leave one lesssealed for insertion of nasal instruments). FIG. 4f shows a similararrangement for the mouthpiece where moving the lever 425F to the leftinflates the seal, occluding or closing off the mouth. Moving levers tothe right draws air from the cuffs to deflate them. In this arrangementthe cuffs are connected for simultaneous seal formation on bothnostrils, i.e. the cuffs are simultaneously inflated. It is possible toselectively seal/partially occlude either the patient's nose or mouth.Alternatively it is possible to selectively seal/partially occlude bothof the patient's nose and mouth. In a further alternative, it ispossible to selectively seal/partially occlude either the patient'snostril or mouth and nostril in combination.

It may still be possible to insert instruments through/past the seals.E.g.: a video-guided bronchoscope may be used through the centre of theinflated mouth seal where limited direct visualisation of the airway isrequired. This enables respiratory support and delivered pressure to bemaintained throughout the procedure and as the interface can hold apartial occlusion, partial seal, or complete seal around the scope. Thepartial occlusion may be fixed or variable by the clinician. Thecontinued delivered pressure can help also to keep the airways patent.

As an alternative, the addition of part of the interface could create orremove a seal. See FIGS. 5a and 5b . Flow is only delivered to theprongs 505. It is assumed that if a mouthpiece is desired, it is toprevent leak and increase the delivered pressure. Therefore, it may bedesirable to also seal the prongs 505. Here the insertion of themouthpiece simultaneously inflates the cuffs 527 by activating theintegrated syringe to push air into the prong cuffs. The cuffs 527 maybe pre-inflated and deflated by a user or clinician or may be deflatedand inflated by a user or clinician.

Where prong cuffs are inflated, they may act to reduce leak from theairway, partially or fully seal. It may be most beneficial to reduceleak so that with a large gas flow to the patient a higher pressure isachieved but maintaining a large leak flow between the prongs and thenares. This may be useful to maximise the effects of CO₂ flushingachieved with high flow and to allow expiration and prevent barotrauma.Prong cuffs may be inflated and deflated from a distance away from thepatient via a small diameter conduit that transfers the air to thecuffs.

The gas supply may contain a pressure relief valve to preventhyper-inflation (e.g.: in the case of a continuous flow delivery and afully sealing interface).

An interface, such as a nasal cannula, may be modified or designed so asto allow for improved or greater ease of insertion or application ofinstruments into the patient's airway. This alternative is describedbelow in relation to the embodiment shown in FIG. 21.

The high flow gases, such as air or air/oxygen mixture or high flowoxygen, can be selectively delivered into the patient's nares via nasalprongs or into the mouth via a mouth piece. Alternatively, the gases canbe delivered to both patient's nares and mouth with minimal occlusionfor high flow delivery. The clinician can also selectively apply apartial occlusion or complete occlusion/seal to either airway. Thepartial occlusion may be fixed or variable by the clinician.

With reference to the embodiments of FIGS. 4a to 5b , the interfaces maypartially occlude, partially seal, or completely seal the patient'snares or mouth.

The mouthpiece of FIGS. 4A-5B could also have extended section as inFIG. 3b or 3 c or 3 d.

The interfaces shown and described in relation to FIGS. 3A, 4A-5B aremodular and customisable. The interfaces described allow a clinician toselectably seal the patient's nose or mouth using one of the interfaces.The clinician may selectively create a seal or partial seal/occlusion inthe patient's nostrils, mouth or create a partial seal/occlusion inboth.

With reference to FIGS. 6a to 6c , another configuration of the userinterface is shown. This configuration is a modification or alternativeto the configurations shown and described in relation to FIGS. 4a to 4fand FIGS. 5a and 5b . An advantage of this configuration is that itrequires no intervention from the user or clinician to create/release orrelease an occlusion or seal.

FIG. 6a shows a mouth insert 611 a that can be used to control pressuresupport (could be used with nasal cannula, e.g.: could be used in one ofthe configurations described above). The mouth insert opens/closes orpartially closes with patient's inspiration/expiration, e.g.: opening orclosing could be controlled by a valve triggered by negative inspiratorypressure.

For example see FIG. 6b : a pressure line 631 runs from the right handside of the mouthpiece (into patient's airway) to above a cavity thatcontains a cover slip 629. When patient inspires a negative pressure isgenerated in the pressure line 631, creating a small vacuum in thecavity and holding the cover slip 629 up, so the mouthpiece 611 is openallowing air to flow to the patient. When patient expires, the pressureis positive forcing the cover down, closing off mouthpiece.

This could be useful if the clinician wants to reduce the inspiratoryresistance to flow, or promote CO₂ flushing by allowing the nasal flowto pass out of the mouth during inspiration, and also wants to provideincreased pressure during expiration, or PEEP to maintain open alveoliin the lungs to aide in lung recruitment, and/or to prevent airways fromcollapsing.

In the opposite case, the cover 629 may be closed during inspiration,and open on expiration. This could be useful if the clinician wants tolimit inspiratory entrainment through the mouth (i.e.: have flow onlydelivered through nasal cannula), to prevent entrainment dilution ofnasally delivered flow. However they may wish to release pressure onexpiration if there is a risk of barotrauma (pressure is higher onexpiration with high flow because of the opposing flows between thedelivered flow and the patient's expired breath.)

Advantages of these configurations shown and described in relation toFIGS. 4a to 4f , FIGS. 5a and 5b , and FIGS. 6a to 6c include:

-   -   Interface is modular and customisable.    -   Allows partial or complete sealing of the airways and therefore        increased pressure delivery compared with normal unsealed nasal        cannula, but design may be less claustrophobic to patient than a        face mask, improving tolerance and therefore the ability to        delivery therapy continuously.    -   Allows insertion of instruments, into mouth and/or nose, without        having to remove interface.    -   Allows insertion of instruments while still being able to        maintain respiratory support    -   Can deliver more than one respiratory support simultaneously.    -   Unrequired parts of interface can be removed, reducing bulk on        the face and improving patient comfort.    -   Design may be less claustrophobic to patient than a mask,        improving tolerance and therefore the ability to deliver the        therapy continuously/effectively.    -   Design allows insertion of oral/nasal instruments without having        to remove interface.    -   Design allows option to insert oral/nasal instruments while        retaining interface occlusion/seal.    -   Delivered pressure can be easily and immediately increased or        decreased, either completely or variably.    -   Mouth insert can hold mouth open for instrument insertion or in        a particular shape for ‘blind’/visually guided intubations or        insertion of other airway devices such as bougies.    -   The mouth insert may be made of a rigid material to help keep        the mouth open, allowing instruments to be inserted, better        visualisation of airway and preventing patient's biting on        instruments, damaging them.    -   When occluded/sealed and used with nasal high flow, the mouth        insert prevents pressure loss from an open mouth, and ensures        accurate oxygen/drug delivery by preventing entrainment through        the mouth.    -   Selective sealing by selective inflating or deflating.

It may be desirable to independently, or dependently control thedelivered flow/pressure through a mask and cannula used together. Thismay be useful in cases when anaesthetists want to be able to ventilatevia a high flow nasal cannula but may also be more familiar with using amask. Ventilation is possible due to the pressure that can be created byusing the interfaces described while still gaining the benefits of highflow therapy delivery.

The user may wish to have better control over the delivered pressureand/or the amount of CO₂ flushing. In addition, hypercapnia can be aconcern, particularly during apnoea.

A proposed solution is to provide independent and dependent control ofmask and cannula delivered flows.

With reference to FIG. 7, another configuration of the user interface isshown. This configuration has a mask 711 applied over the nasal cannula701 and prongs 705. The mask seal 730 may have a compressed section 731that can easily mould over the cannula tube, e.g.: FIG. 7b shows across-section through the seal. The mask 711 may clip onto the cannula701.

According to the disclosure, the interface is configured and adapted toallow intrusion of the gas conduit 702 into the interior volume of themask 711, while maintaining the substantially gas tight seal between themask and the user's face and/or the spacer component provided on theuser's face.

The mask 711 comprises one or more accommodation sites or portions 733adapted to facilitate intrusion of the gas conduit into the interiorvolume of the body while maintaining the seal between the interface andthe user's face. The one or more accommodation sites or portions 733 isprovided on or adjacent the seal and/or the body. In the embodimentshown, the accommodation site is provided as a cut-out in the seal. Thecut-out has a profile which is similar, or slightly smaller in dimensionthan the cross-section of the gas conduit. This is so that the gasconduit can extend into or out of the interior volume of the bodywithout leaving a gap between the seal and the user's face which willthen compromise the seal between the seal and the user's face.

The accommodation sites or portions of the interface may allow for theinterface to be used with a nasal cannula.

The nasal cannula 701 is used to deliver a relatively high flow ofoxygen or a high flow of blended gases or high flow of air. The mask maybe used for various other respiratory support or for anaestheticsdelivery. As mentioned above, the mask comprises a seal to seal againstthe user's face when in-use.

The accommodation sites or portions 733 allow for the nasal cannula tobe used with the interface without compromising or substantiallyaffecting or interfering with the seal between the interface and theuser's face. This may allow for a nasal cannula 701 which for exampledelivers high flow therapy to be used in combination with the mask 711which is used to provide other respiratory support. A medicalpractitioner can adjust or choose which respiratory support to be usedon the user without irritating the user by constantly adding or removingthe user interfaces, such as the mask and the nasal cannula.

In some other configurations, the accommodation sites or portions allowsthe interface to be put on a user without first removing the nasalcannula from the user's face. Various sealing structures may be utilisedto facilitate a greater ease of switching between respiratory supportmodes without the need to change or remove one, some or any or allpatient interfaces.

The accommodation site or portions may be provided directly in the sealand/or the body of the mask such as that shown in FIGS. 7a to 7c . Inanother embodiment, the accommodation sites or portions may be providedas an extension portion of the seal and a cut-out is formed in theextension portion instead of directly in the seal.

A method of providing respiratory support to a patient will now bedescribed. A nasal cannula 701 is placed upon a face of a user in anoperational position, the nasal cannula having a body portion and atleast one nasal prong extending from the body portion.

Next, a mask 711 is placed upon the face of the user. The oro-nasal maskhas a body. The body comprises an aperture or a port 735 allowing forcommunication of gases to and/or from a gas supply or source to aninterior volume of the interface. The interior volume 737 is defined byan interior of the body and the face of the user when in-use, a sealprovided for creating or forming of a seal between the user interfaceand the user's face and/or a spacer component (not illustrated) providedon the user's face. It will be appreciated that accommodation sites willnot be necessary if a spacer component is used because the spacer can beappropriately shaped.

A seal is created or formed between the mask and the user's face and/orthe spacer component (not illustrated) so provided on said face.

A flow of gas is directed into the user's airway via the nasal prongand/or the oro-nasal mask.

The following cases of mask and cannula delivered flows are possible:

-   -   Case 1: High flow may be delivered though the cannula and mask        simultaneously, from one or different gas sources. This could be        used for mouth breathers to ensure high flow is delivered        effectively (preventing mouth entrainment of room air)    -   Case 2: FIG. 7c . Positive flow delivered through mouth, mask        flow is negative (suction). This may help promote CO₂ flushing        in the airway. Especially if the mouth is open—this could        encourage flow circulation in back of pharynx. The narrowing of        the airway at the back of the mouth may act as a venturi,        entraining even more flow from the cannula than the patient may        naturally inspire, and further promoting flushing. If the        patient is apnoeic (and not naturally inspiring) this flushing        would also be beneficial.    -   Case 3: reverse of case 2. May be more comfortable for some        patients (e.g.: mouth breathers)    -   Case 4: reverse of case 2 but high flow is delivered through        mouthpiece, or tube inserted in mouth    -   Case 5: flow is varied between case 2 and case 3 (e.g.: once        every breath cycle). This may create greater turbulence in the        airway, promoting gas mixing, and further promoting CO₂        flushing, or at a higher frequency (e.g.: 100 Hz)    -   Case 6: High frequency oscillations though one interface, with a        base flow/pressure through the other. Again to help promote gas        mixing, while maintaining a base level of respiratory support.    -   It will be appreciated the above cases are non-limiting examples        and the delivered flows may be provided by alternative        interfaces or systems.

Conventional high flow interfaces are currently designed only fordelivery of gas to a user through the user's nose. In procedures such asendoscopies (e.g.: bronchoscopies) in can be desirable to providerespiratory support through the mouth so the nose can be accessed. Toachieve this, clinicians may put the nasal cannula in the patient'smouth. This can fall out easily, especially if the patient is sedatedand it is not comfortable. The clinician may not notice the prongs havefallen out and this can lead to ineffective therapy support and patientdeterioration.

With reference to FIGS. 8a to 8h , various configurations will now bedescribed. Each of the following configurations allows the userinterface to be convertible between a nasal cannula configuration and anoral gases delivery interface configuration. In the nasal configuration,the user interface comprises a cannula having a body portion, at leastone prong extending from the body portion, the prong being adapted todirect a flow of gas into a nare of a user's nose. In the oral gasesdelivery interface configuration, the user interface comprises a cannulahaving a body portion, at least one prong extending from the bodyportion, the prong being adapted to direct a flow of gas into a nare ofa user's mouth, and a mouthpiece adapted to surround the at least oneprong of the cannula and an outer periphery that substantially conformsto the area of a user's mouth. The mouth piece allows the cannula to beconfigured to comfortably fit in the user's mouth.

With reference to FIGS. 8a and 8b , another configuration of the userinterface is shown. In this configuration, an insert 811A clips over thecannula 801A. The insert 811A is advantageously shaped to the user'smouth. This configuration allows flow from the prongs 805A to bedirected into the user's mouth. This embodiment may contain an opening812A on the mouthpiece to allow venting/exhalation when in the user'smouth. The clip-over section may be bought as separate part. The cannulacan be left as normal until adaption is required. The flow of gas isprovided to the interface by a gases conduit 802A.

With reference to FIGS. 8c and 8d , another configuration of the userinterface is shown. This configuration has a mouth piece 811C thatslides up the main cannula body on rails 839C. The user interface hasstops on the rails to prevent the mouthpiece completely sliding off,which also prevents the mouthpiece 811C being lost. In thisconfiguration, the tube 802C can sit well outside mouth. The mouthpiecesdescribed herein can be shaped to fit into the patient's mouth andcreate a complete or at least substantial seal with the mouth. Themouthpieces of FIGS. 8a-8d are soft so as to sit comfortably in themouth and/or seal in the mouth.

With reference to FIGS. 8e and 8f , another configuration of the userinterface is shown. This configuration has prongs 805E that inflate tosubstantially or completely fill the area of a user's mouth or nose toincrease pressure delivery or create a complete seal. The interface hasinflatable cuffs 827F that may inflate to fill the gap in the centre,between the prongs, to prevent mouth leak when the interface is insertedinto the mouth. The cuffs 827F may be pre-inflated and deflated by auser or clinician or may be initially deflated and inflated by a user orclinician. Alternatively, the cuffs may allow mouth leak by beingpartially inflated, if desired for example to reduce resistance forexpiration. The cuffs may be partially inflated for smaller mouths. Thecuffs may be used to increase pressure delivery during nasal therapy. Anadvantage of this configuration is that the main cannula body can besmall as the cuffs are used to create the additional volume that may benecessary to sufficiently occlude the nares to deliver effectivetherapy.

With reference to FIGS. 8g and 8h , another configuration of the userinterface is shown. This configuration has an inflatable mouth cuff 841g that rises up off the manifold. The cuff 841 g may be pre-inflated anddeflated by a user or clinician or may be initially deflated andinflated by a user or clinician. The cuff may also have opening (notshown) to keep the interface unsealed. The cuff can conform to arequired shape such as the patient's mouth, which may be morecomfortable for the user's mouth and/or may create a better seal in theuser's mouth. The cuff may be or comprise a soft, flexible material.

In some configurations described above, the interface may comprise aheadgear assembly for locating the interface on the face of the userin-use.

In some configurations, the headgear can be a bifurcated headgear with apair of rear straps that engage the rear of the patients head. In yetsome other configurations the headgear can comprise at least one rearstrap to engage the rear of the head or the occiput of the head, and atop strap to engage the top of the user's head.

Where headgear is utilised, the headgear may be configured to providefor a resultant vector force such that the interface, such as the mask,is held on the face with minimal force on the user.

Alternatively, the interface may not comprise any fixing means such as aheadgear and a medical practitioner places the interface at a suitableposition on a user's face and then gently pushes the interface towardsthe user's face to sealingly engage the interface with the user's face.

In one embodiment, there is provided a patient interface (not shown)that comprises at least one delivery element 1 for delivering ordirecting a flow of supplied gas to a nare or the nares of a user'snose, wherein each delivery element 1 comprises of at least one lumen 2through which said flow of supplied gas is directed, and wherein theflow of supplied gas is modified according to one or more forms 3 thatis/are provided within or about an interior of one or more of said atleast one lumen 2.

In one embodiment, a patient interface (not shown) including a deliveryelement 1 provides for a gas flow through a lumen 2 of such a deliveryelement 1. Such a gas flow can have a turbulent kinetic energy that isthe kinetic energy associated with eddies in turbulent flow. Flows withhigher levels of turbulence can have a higher skin friction (drag) andtherefore require a larger pressure to drive a given flow rate.

Delivery elements may comprise one or more forms, such as which may beone or more of: bumps, ribs, rifling, irregular shaped cross-sections,serrated edges to the delivery element 1, to change whether byincreasing or decreasing the level of turbulent kinetic energy beingdelivered to an airway of a user. In some configurations, an increase ordecrease in the pressure generated in the airway may result.

FIG. 9A (a) shows a helical form 3 extending along at least a part ofthe length of an interior wall surface of a lumen 2 of a deliveryelement 1.

FIG. 9A (b) shows ridges or longitudinally extending projections asforms 3 along at least a part of the interior wall surface of a lumen 2of a delivery element 1, this view can also be used as an example of thecross-sectional view of FIG. 9A (c).

FIG. 9A (c) shows lumps or bump type forms 3 positioned in the lumen.

These may be positioned in a localised region of a delivery element 1,closer to the outlet of the element 1 than the inlet relative to thedirection of flow of supplied gas.

FIG. 9B (a) shows a serrated edge or serrated rim region as a form 3 ofa delivery element 1.

FIG. 9B (b) shows the end view of FIG. 9B (c) in which a region towardthe end or an outlet of the delivery element 1 includes a generallyrippled or corrugated or wavey-type form 3.

FIG. 10A (a) and (b) show an end view and a cross-sectional view of adelivery element 1 that comprises forms 3 as a series or arrangement ofpartitions in a generally honey-comb or hexagonal type configuration.

FIG. 10B shows forms 3 as a series of partitions in a grid or mesh-likearrangement or array.

FIG. 10C shows forms 3 as a concentric arrangement of walls orpartitions, which in this configuration include the optional addition ofa bi-secting wall or partition as a further form 3.

Turbulent flows may dissipate more readily than laminar flows. A laminarflow of gases (e.g. a jet type flow) for a given flow rate willtherefore likely have a greater penetration depth into the nasal cavityor an airway than a turbulent flow of gases.

In some configurations, a laminar or directional flow of gases maytherefore be more advantageous for delivering flow in a targeted mannerand delivering a higher pressure to the patient's airway or to lowerareas of the patient's airways to reduce the chance of collapse in theairways.

A more laminar flow of gases may be promoted by adding various forms 3,such as flow straighteners to the inside of the delivery element, suchas nasal prongs and/or a manifold of a patient interface, such as anasal cannula. These forms or flow straighteners could be any particularfeature that directs the flow into parallel streamlines such as ahoneycomb mesh, grid mesh, concentric rings, flow vanes etc. (see FIG.10a-c ). Forms 3 can be used to align the gas flow path as the gastravels through the delivery element 1, and in this way, the gas flowcan be directed or focussed so as to achieve such a more laminar or lessturbulent type flow.

For example, the forms 3 can be used to channel the gas flow in such away as to minimise or reduce the likelihood of an increase inturbulence, preferentially in certain situations decreasing theturbulence.

In yet other configurations, the delivery element may be a directionallyoriented or angled element with respect to the user or their airway.

For example, in some configurations, relatively higher levels ofpressure in the lungs may be created with such relatively high gas flowrates, such as in situations when the flow velocity from the cannulamaintained higher for longer. This may be due to a dynamic pressurecomponent of the gas flow, which may translate into an elevated staticpressure when the gas flow slows down in different parts of the airway,for example the lower airways.

The Coanda effect, which is the tendency of a fluid flow to attach to asurface can be utilised by having purposefully orientated cannula prongsthat direct the flow to be attached to any surface in the nasal cavityor a surface of a user's airway.

A gas flow attached to a nasal cavity or other airway surface is morelikely to maintain its high velocity through the nasal cavity or suchother airway surface and provide more dynamic pressure following thenasal cavity and the other airway surface and reduce flow dissipation.

In yet further configurations, delivery elements, such as a nasal prong,can be inwardly angled (such as toward a user's septum in-use, or towarda patient's mid-line or sagittal plane), for example in this way the gasflow can attach the flow to the septal wall, inferior angled prongs canattach the flow to the floor of the nasal cavity, and superior angledprongs can attach the flow to the upper surfaces of the nasal cavity.Multiple delivery elements provided in an airway, such as nasal prongsprovided in one nostril, can be orientated in different directions mayalso enhance the pressure delivered (see FIG. 11). FIG. 11 shows twoexemplary prong orientations. One orientation is when the prong isangled downwards, that is, an inferior angle. The other orientation is asuperior angled prong that attaches flow to the top surface of thenostril.

In other configurations, the delivery element may provide for a gas flowmultiplier or multiplication effect.

In some embodiments, for example where the gas flow is a jet-type flowemanating from the delivery element (such as a nasal prong), there canbe created a high level of viscous shear on the surrounding air in theatmosphere and inside the airway or a user's nostril. This viscous shearcan drag additional room air (or other gases provided to the vicinity ofa user's airways, such as the nares of their nose) and into the airway,such as the nasal cavity, along with the flow delivered through thedelivery element itself. The shape of the delivery element (e.g. nasalprongs) can be made to enhance this flow multiplier effect to increasethe effective flow delivered to the patient. Higher delivered flows cancreate higher airway pressures. In some cases however the deliveryelement may be shaped to minimise the flow multiplier effect such thatdilution of the gas, such as a warmed and humidified delivered gas,which otherwise supplements colder and dryer room air, is minimised.This is advantageous because gases can be saved and a there may areduced need for a powerful flow generator to be used.

In yet further configurations, the delivery element may provided for anextended flow pathway into a user's airway. For example, where thedelivery element is a nasal prong, relatively long prongs may beemployed with a patient interface.

It is desired for the pressure to be transmitted to the lungs,retardation of the flow velocity in the nasal cavity by the nasalresistance reduces the dynamic pressure of the delivered flow and isundesirable. A single long prong or a long prong in each nostril thatterminates proximal of the nostril will increase the delivered dynamicpressure as the termination point approaches the lung.

The prongs could for example terminate proximal of the nasal valve(which imposes a large flow resistance) or terminate in the velopharynx(another narrowing that imposes a large flow resistance) such that theflow is targeted directly inferior towards the lungs (in this location aflow multiplier effect may occur as the turbulent flow passes the oralcavity and flow is entrained through the oral cavity). Long prongs mayoffer the advantages of reduced noise and higher tolerable flow ratessince we are bypassing the sensitive nasal epithelia.

The prongs could for example be angled to reduce the back pressurecreated by restrictions in the airway, such as the nasal valves, andincrease the jetting/flow delivery into the lungs. For example, theprongs could be angled so that flow passes centrally through the nasalvalve.

The length of the prongs may also be dynamic i.e. they can eitherautomatically or manually grow in length via mechanical or chemicalprocesses i.e. a dial increases their length, they are telescopic, orupon application of humidity, temperature or an electrical current theprong material expands in a longitudinal direction.

In some configurations the prongs may comprise concertina arrangementsthat are configured to expand the prong (i.e. increase prong length)when there is a high flow rate. Other embodiments may be utilised so asto provide a delivery element 1, such as a nasal prong, with the abilityto grow or expand in length dynamically in response to an input (e.g. acharacteristic of the gas, such as flowrate or pressure or temperatureor humidity or other stimuli such as electrical impedance or otherelectrical characteristics which may be incorporated into such adelivery element 1).

In yet other configurations, the delivery element may provide for arelatively small area or smaller cross-sectional area of flow pathavailable to the gas as it is transmitted through the delivery element.In situations where the delivery element is one or multiple nasalprongs, such prongs may have a relatively smaller area or a relativelysmaller outlet.

Small area prongs can be used to increase the velocity of a given flowexiting the prongs. Small area prongs provided a greater turbulence ofairflow and/or pressure in the lower airways of the patient. Theincreased velocity increases the dynamic pressure and energy of the flowleading to a larger pressure being communicated to the lower airways.The small area prongs with nominally a diameter of less the 30% of thenostril diameter can be used in combination with either turbulators,flow straighteners or directional prongs to achieve higher airwaypressures in different cases.

Alternatively, in yet other embodiments, relatively larger areacross-sectional area of the delivery element or an outlet from thedelivery element may be provided. In those situations where nasal prongsare utilised, such prongs may have a relatively larger cross-sectionalarea or outlet.

Large area prongs refer to nasal prongs that substantially fill thenostrils and have a diameter equivalent to about 30%, about 50%, about70% to about 100% of the nostril diameter, or fill about 30%, about 50%,about 70% to about 100% of the nostril cross-sectional area. Byincreasing the area of the prong, the flow velocity exiting the prong isreduced for a given flow rate. Therefore, higher gas flow rates could bedelivered with a large area prong than a standard nasal prong for thesame flow velocity. High velocities may be undesirable in some cases asthey could be uncomfortable (noise, vibrations, abrasion) or lead todetrimental effects on sensitive nasal epithelia. High flow rates aredesirable in the case of anaesthetic applications in particular(although not limited to) because given the mouth is open, the pressurereceived by the patient in the lungs is largely flow rate dependant andgoverned by the oral resistance to flow of the gas flow in turn exitingthe mouth. Additionally, large area prongs reduce the leakage areabetween the prong and the nostril allowing higher pressures to bedelivered to the nostrils and subsequently into the lower airways.

In still further configurations, a pressure relief manifold mayoptionally be incorporated into the patient interface, such as a nasalcannula, circuit or delivery system to ensure a maximum deliveredpressure if the mouth is to close during treatment. The pressure reliefmanifold could be manual or automatic e.g. a port or valve that could besealed manually using valves or other sealing systems, or throughmechanical or electrical operation automatically limit the maximumpressure and/or rate of rise of pressure delivered to the patient. Suchseals or valves may also comprises of a one way valve and be used topreferentially deliver pressure on inspiration or expiration. Occludingor occupying a substantial percentage of the nostril area can beachieved in a number of ways, for example:

-   -   With reference to FIG. 12, compliant walled prongs 5—Prongs made        with a material and/or wall thickness that allows significant        stretch for a given applied pressure (compliance) may be used        such that the prongs expand to at least substantially fill the        nostrils upon application of a flow rate to substantially        occlude the nostrils. The prongs may be shaped in such a way to        further facilitate this action (e.g. bulge into a balloon shape,        see FIG. 12) or include a flow restrictor at the end of the        prong to increase the inflating pressure inside the prong. The        compliance of the prong walls may be selected such that        different levels of compliance provide different levels of        nostril occlusion and therefore different pressure ratings.    -   Prongs that are made from a material that actively or passive        expands or grows with the application of humidity, an electrical        current, temperature, or other input or parameter such that the        prongs substantially fill the nostril area.

In further embodiments, the delivery element, such as nasal prongs, mayprovided for sealing or non-sealing of the airway into which it or theyare to be located. With reference to FIG. 13, the difference betweenlarge area prongs and sealing prongs is that sealing prongs seek toachieve a 100% seal and this may be achieved in combination with a smallarea prong without necessarily having a large area prong i.e. a smallarea prong surrounded by an inflatable cuff, 4.

Sealing or optionally sealable prongs on cannula (e.g., inflatableprongs or inflatable outer cuff). Inflatable portion could be connectedto actuator on cannula or machine that instantly inflates them from agas source when additional pressure is desired to create an occlusionwith the nares or nostrils of the patient. The inflatable portion couldalso be connected to a tap off the main gas source (i.e., as thedelivered flow rate is increased it is assumed more pressure is desiredand the prong seal is increased).

Prongs with an outer inflatable cuff 4 that either expand to fill thenose automatically with flow applied or are inflated with a syringe oranother manual or automatic flow or pressure source.

In cases where a perfect seal is not desired (i.e. for comfort or tolimit the pressure delivered), ribs may be added to one or both of theouter face of the prongs to ensure a leakage area even when the prongsare fitted into the nostrils with a tight tolerance.

In still further embodiments, the delivery element can includefacilities or other accommodation sites or regions to allow for theinsertion of other devices into the user's airway or parts of theirairway.

Pressure delivery devices such as nasal cannula and masks typically needto be removed to in order to insert nasogastric tubes, bronchoscopes orother airway equipment (e.g. bougie). This leads to an interruption oftherapy which can have a significant detrimental effect on the patient.The large area prongs and sealing prongs may include a valve to allowinsertion of such a device so that airway pressures can be maintained atan elevated level without interruption. Alternatively, the prongs mayseal around the device/instrument 2140, as shown in FIG. 21. Enablingpressure to be delivered during a procedure such as a bronchoscopy alsohas the advantage of improving airway patency making the bronchoscopyitself easier to perform. FIG. 21 shows a patient interface 2100 havingprongs 2105 with cuffs 2127. The cuffs have one or more passages 2141for receiving the device/instrument 2140. The cuffs may completely sealaround the instrument, or partially seal around the instrument.

Relatively high gas flowrates may be utilised in the devices, systemsand methods of this disclosure. For example, it may be suitable toprovide for gas flowrates of up to about 70 L/min to give significantlylonger apnoeic oxygenation times, relative to say about 40 L/min. Incombination with a dead space flushing effect, this is likely due to theincreased pressure delivered at 70 L/min compared with lower flows.Given that dynamic pressure is proportional to the square of velocity(linearly related to flow rate via Q=VA), a doubled flow rate will leadto four times the pressure delivered.

Accordingly, in combination with one or more of the configurations orembodiments disclosed herein, delivery of flowrates of about 70-200L/min may be utilised.

Still further embodiments of this disclosure include use of a system forcontrolling “mouth leak”. In an anaesthetic application or other medicalprocedure, but not solely limited to this, the mouth may be open for theprocedure. Pressure delivered via the nose is naturally limited by flowleakage out of the mouth. The leakage of flow out of the mouth duringsuch a procedure may be reduced or eliminated by using an oral insertthat controls and/or blocks the leakage flow. The insert may be amouthpiece. The mouthpiece may be a bite block. The mouthpiece may haverelatively large openings that are adapted to receive instruments. Thiscan also create a leakage path for flow delivered to the nostrils.

A mouthpiece may comprise of a hollow opening filled with a membraneand/or valve used to gain access to the airway. Procedural equipment maybe able to easily pierce through the membrane, and or pass through thevalve and maintain a seal around the mouth and equipment.

A bite block may utilise a spring or other self-opening mechanismbetween two components to assist in holding the mouth open. Othermouthpieces that engage the patient's mouth may also be used other thana bite block.

The “mouth leak” may be controlled using a mouth piece that partiallyoccludes, partially seals, or completely seals outside the patient'steeth, inside the patient's teeth, outside the patient's lips, insidethe patient's lips, and/or partway down the patient's mouth. That is,the mouthpiece may be a two-level occlusion or seal. In yet furtherembodiments, there is a desire for the maintenance of airway pressure.As outlined herein, it can be advantageous to maintain an elevatedairway pressure without interruption. Incorporation of a battery with ananaesthetic specific flow source or a general high flow source of gasesis therefore contemplated in order to maintain therapy when a patient oruser is being transported from theatre to the recovery room (or from onelocation to another).

It may be desirable to provide airway pressure via a mask while a nasalcannula is in place. For this case, the nasal cannula gas supply conduitor tubing may be collapsible in the region where the mask contacts theface in order to allow a better seal between the mask and face,facilitating a higher delivered pressure.

In yet other embodiments, there is a desire for pressure control.Contemplated are methods for estimating the pressure delivered to apatient via a patient interface, such as a nasal cannula capable ofdelivering the relatively high flowrates disclosed herein. It will beappreciated the flow source may need to be automatically or manuallyadjusted to maintain a delivered airway pressure that meets a prescribedtarget value or range. This could be controlled electrically ormechanically. Rather than supplying a flow source with a flow controldial (or similar) the dial may allow pressure control and incorporatesome safety flow or pressure limits.

It is possible to detect when a patient is asleep and breathingspontaneously (either asleep naturally or under anaesthesia), forexample by using particular technology and/or monitoring the respiratoryrate and respiratory rate variability via pressure fluctuations in anasal cannula and/or a system capable of delivering the relatively highflowrates disclosed herein.

In a similar manner it can be detected if anaesthesia has taken affectand paralysed respiration such that the respiratory rate is zero. When asleep or apnoeic state are detected it may be desirable to automaticallyincrease the flow and pressure delivered to a prescribed or defaultlevel.

Given that atelectasis can remain for several hours after surgery andlung collapse reoccurs rapidly after discontinuation of PEEP, it isdesirable for an anaesthesia flow source to have a ‘recovery’ functionin which the airway pressure is gradually reduced automatically overtime and the patient weaned off to natural breathing. The airwaypressure can be reduced by controlling the interfaces to graduallyremove the occlusion/seal from the nasal prongs or from the mouthpiece.The length of time of recovery may be inputted and the rate of pressurereduction calculated automatically with a linear or non-linear functionor the rate of pressure reduction inputted itself. A default setting mayalso be used. An indicator (visual, or auditory or even haptic) may beused to show the patient has had their pressure or flow weaned to adesired level.

Disclosed is a Lung Recruitment Device.

A further embodiment relates to an interface used for performing lungrecruitment manoeuvres. In one form, the interface comprises a sealwhich can be selectively activated or used to create or form anocclusion, a partial seal, or a seal, between the user interface and theuser's nose and/or mouth. When the occlusion, partial seal, or seal isformed between the interface and the patient's nose and/or mouth, lessgas is leaked out of the system which allows a temporary increase indelivered pressure to aid lung recruitment.

FIGS. 14A and 14B show an exemplary embodiment of such interface whichcomprises a seal 13 which can be selectively activated to create or forman occlusion, partial seal, or complete seal to thereby temporarilyincrease the pressure delivered to the user. In this example, theinterface is a nasal cannula 10 comprising two nasal prongs 12 whichextend into nares of a patient when in-use. The prongs 12 generally donot seal against the nares of a patient, which means some gases will beleaked from the prong outlets to the surrounding atmosphere.

In accordance with the disclosures, the nasal prongs 12 each comprise aninflatable seal 13 for example on or surrounding the exterior of theprongs 12. When the seal 13 is in the deflated state, the nasal prongs12 simply extend into the nares of a patient without forming a seal withthe nares of the patient. In the inflated state, the seal 13 inflates,which increases the cross section dimension of the prongs 12 to allowthe prongs 12 to seal against the nares and therefore prevent or reducethe gas leakage which would otherwise occur without such sealingarrangement.

In the embodiment shown, the seal activation mechanism comprises a plug14 which controls the opening and closing of a gas flow path which leadsto an interior cavity of the inflatable seal 13. When the gas flow pathis open, gas is directed to flow into the seal interior cavity toinflate the seal 13. The plug 14 is biased by a spring 16 to remain inits generally closed position as shown in FIG. 14A. When the plug 14 ispushed down as shown in FIG. 14B, an orifice 15 in the body of the plug14 aligns with the gas flow path to create an open pathway for thegases. Once the seal is inflated, the plug 14 may return to itsgenerally closed position to keep the gases within the seal 13.

FIG. 17 shows an alternative embodiment that can be selectivelyactivated to create or form an occlusion, partial seal, or complete sealto thereby temporarily increase the pressure delivered to the user. Inthis embodiment, the interface 1701 may include removable adaptor(s)1727 to fit over the interface, for example over the prongs 1705. Theadaptors may be different sizes to create greater/lesser occlusion anddeliver greater/lesser pressure.

FIGS. 18 and 19 shows an alternative embodiment that can be selectivelyactivated to create or form an occlusion, partial seal, or complete sealto thereby temporarily increase the pressure delivered to the user. Theprongs 1805 may have tapered portions or components 1827 with increasingcross sectional diameter further from the outlet of the interface(further from the patient). The interface 1801 can be inserted more orless distance into airway to create greater/lesser occlusion.

FIG. 20 shows an alternative embodiment that can be selectivelyactivated to create or form an occlusion, partial seal, or complete sealto thereby temporarily increase the pressure delivered to the user. Theinterface 2001 may have an adapter in the form of discs or rings 2027 ofincreasing size further from the outlet of the interface 2001. The discsor rings extend outwardly from the prongs 2005. The interface 2001 canbe inserted more or less distance into airway to create greater/lesserocclusion.

Another user interface which may be used as a lung recruitment device isa mouth piece, which may be used separately or in conjunction with thenasal cannula of FIGS. 14A and 14B. FIGS. 15A and 15B show an exemplarymouth piece 17. The mouth piece 17 may be a bite-block. The mouth piece17 comprises a flange 18 which is to be inserted in the mouth of a user,and which preferably sits behind the teeth of the user when the usercloses the mouth; and a biting portion 19, for the user to bite. Thebiting-portion 19 may be formed into a hollow cylindrical shape or otherdesirable shape, to allow a tube or other airway devices or instrumentsto be inserted through a passage 20 formed in the biting portion 19, orjust allow the patient to exhale through the mouth piece 17 via thepassage 20. The hollow cylindrical shape may be a rigid shape.

In this embodiment, the interior of the passage 20 may also comprise aninflatable seal 22. The seal 22 comprises an associated seal activationmechanism controlling the inflation or deflation of the seal 22.Inflation of the seal 22 closes or at least reduces the size of thepassage 20. The mouth piece 17 may use a similar seal activationmechanism such as that used in the nasal cannula of FIGS. 14A and 14B.For example, the seal 22 may be activated by a user pushing a plug 21 inthe direction indicated in FIG. 15B. When such mouth piece 17 is usedwith the nasal cannula of FIGS. 14A and 14B, it prevents or reduces thedelivered gas escaping from the mouth which would otherwise reduce thedelivered pressure from high flow.

FIGS. 16A and 16B show a different embodiment of a mouth piece 17 whichcomprises a passage 20 which is selectively closed or at least reducedin size when the seal activation mechanism is activated. The mouth piece17 has a similar structure as that shown in FIGS. 15A and 15B but uses adifferent activation mechanism. As shown, the front flange 24 of themouth piece 17 may comprise a clamp 23 causes the passage 20 to close orreduce in size when it is pushed down into a slot of the front flange.

In some configurations, the interface may include a pressure sensor todisplay pressure to a user. This may be useful in case of constantdelivered flow (e.g., high flow) which will cause increasing pressure asflow is left running into a sealed airway.

Some Advantages of the Present Interfaces are:

-   -   increased pressure delivery helps to improve ventilation/gas        exchange by preventing and treating atelectasis and promoting        lung recruitment    -   the increased occlusion may be implemented in a modular and        customisable interface where the occlusion may be increased        independently in each of the nares and the mouth: the        respiratory support may be delivered through nose and/or mouth    -   they allow insertion of instruments without loss of therapy    -   they provide partial occlusion of airways, which is advantageous        because it prevents atelectasis, prevents alveoli collapse,        and/or promote lung recruitment while still providing the        benefits of high flow delivery.

The embodiments described herein allow a clinical to increase thepressure delivered to the patient by at least partially occluding someor all of the patient's airways (that is, the patient's nasal passagesor mouth) in order to maintain open airways, while still being able toflush CO₂ due to using a non-sealing interface with high flow.Additionally or alternatively, a clinician may not activate the seals onany of the interfaces so that high flow gases can be selectivelydelivered to nose or mouth or both to provide high flow therapy.

In an alternative embodiment, a patient interface may be provided thatallows a clinician to selectively supply air to the patient's nose, thepatient's mouth, or both the patient's nose and the patient's mouth.This embodiment may comprise detachable prongs and mouthpiece to allowselective delivery of high flow to either the patient's nose, thepatient's mouth without applying any occlusion.

The embodiments described herein may provide partial occlusion, partialsealing, or complete sealing. Alternatively, the embodiments describedherein may selectively provide gas flow to the patient's nose, thepatient's mouth, or both the patient's nose and the patient's mouthwithout adjustable occlusion or sealing.

The various embodiments disclosed herein may be provided in combinationwith any one or other of the other embodiments or configurations asdisclosed here.

The foregoing description of the disclosure includes preferred formsthereof. Modifications may be made thereto without departing from thescope of the disclosure.

ITEMS

A1. A user interface comprising:

a nasal cannula having a body portion locatable upon a face of a patientin an operational position, at least one nasal prong extending from thebody portion, the nasal prong being adapted to direct a flow of gas intoa nare of the patient's nose when the body portion is in the operationalposition, a port located at or near the body portion, and

a flow controller for selectively closing the port,

wherein the port and the flow controller plug are arranged to allow atleast part of the flow of gas to vent to control the flow of gas intothe nare of the patient's nose from the nasal prong.

A2. A user interface comprising:

a nasal cannula provided with a cannula gas flow supply,

an oro-nasal mask provided with a mask gas flow supply,

a port located at or near a body portion of the oro-nasal mask, and

a flow controller for selectively closing the port,

wherein the port and the flow controller are arranged to allow at leastpart of the flow of gas to vent to control the flow of gas into thepatient's airway.

A3. A user interface according to item A1 or item A2, wherein the flowcontroller comprises a removable plug.

A4. A user interface according to item A1 or item A2, wherein the flowcontroller comprises a pressure relief valve.

A5. A user interface according to item A1 or item A2, wherein the flowcontroller comprises an adjustable valve.

A6. A user interface convertible between a nasal configuration, an oralconfiguration, and an oro-nasal configuration, the user interfacecomprising:

a nasal cannula having a body portion, at least one prong extending fromthe body portion, the prong being adapted to direct a flow of gas into anare of a user's nose,

a mouthpiece adapted to direct a flow of gas into a user's mouth,

a gas delivery conduit, and

a valve between the nasal cannula and the mouthpiece, wherein

in the nasal configuration, the gas delivery conduit delivers a flow ofgas to the nasal cannula and the valve prevents or substantiallyinhibits a flow of gas between the nasal cannula and the mouthpiece,

in the oral configuration, the gas delivery conduit delivers a flow ofgas to the mouthpiece and the valve prevents or substantially inhibits aflow of gas between the nasal cannula and the mouthpiece, and

in the oro-nasal configuration, the gas delivery conduit delivers a flowof gas to the mouthpiece or the nasal cannula and the valve allows aflow of gas between the nasal cannula and the mouthpiece.

A7. A user interface according to item A6, wherein the nasal cannula andmouthpiece are connected together.

A8. A user interface according to item A6, wherein the nasal cannula andmouthpiece are releasable connected.

A9. A method of providing respiratory support to a patient comprising:

placing a nasal cannula upon a face of a user in an operationalposition, the nasal cannula having a body portion and at least one nasalprong extending from the body portion,

placing an oro-nasal mask upon the face of the user, the oro-nasal maskhaving a body, said body comprising an aperture or a port allowing forcommunication of gases to and/or from a gas supply or source to aninterior volume of the interface, the interior volume defined by aninterior of the body and the face of the user when in-use, a sealprovided for creating or forming of a seal between the user interfaceand the user's face and/or a spacer component provided on the user'sface,

creating or forming of the seal between the mask and the user's faceand/or the spacer component so provided on said face, and

selectively directing a flow of gas into the user's airway via the nasalprong and/or the oro-nasal mask.

A10. A user interface convertible between a nasal cannula configurationand an oral configuration, wherein:

in the nasal configuration, the user interface comprises a cannulahaving a body portion, at least one prong extending from the bodyportion, the prong being adapted to direct a flow of gas into a nare ofa user's nose,

in the oral configuration, the user interface comprises a cannula havinga body portion, at least one prong extending from the body portion, theprong being adapted to direct a flow of gas into a nare of a user'smouth, and a mouthpiece adapted to surround the at least one prong ofthe cannula and an outer periphery that substantially conforms to thearea of a patient's mouth.

A11. A user interface according to item A10, wherein the mouthpiece isclipable onto the cannula.

A12. A user interface according to item A10, wherein the mouth piece isslidable relative to the cannula.

A13. A user interface according to item A10, wherein the prongs areinflatable.

A14. A user interface according to item A10, wherein the mouthpiece isinflatable.

A15. A user interface system comprising a first user interface and asecond user interface, the first interface being an unsealed interfaceand configured for use in conjunction with a second user interface.

10389 ITEMS

B1. A patient interface comprising at least one delivery element fordelivering or directing a flow of supplied gas to a nare or the nares ofa user's nose, wherein each delivery element comprises of at least onelumen through which said flow of supplied gas is directed, and whereinthe flow of supplied gas is modified according to one or more forms isprovided within or about an interior of one or more of said at least onelumen.B2. The interface according to item B1, wherein said form is a, or onemore, surface relief portions or regions provided as part of an internalwall surface of one or more of said at least one lumen.B3. The interface according to item B1 or 2, wherein said form is aprojection extending radially inwardly from or along an interior wallsurface of one or more of said at least one lumen.B4. The interface according to any one of items B1-3, wherein said formis a depression or recess provided within or along a portion or regionof an interior wall surface of one or more of said at least one lumen.B5. The interface according to any one of items B1-4, wherein said formextends in a continuous or discontinuous manner along or about thedelivery element, from a downstream location to a more upstreamlocation, said location being relative to the direction of the flow ofsuppled gas through said delivery element.B6. The interface according to any one of items B1-5, wherein said formcomprises one or more partitions extending along a length and/or acrossa cross-sectional area of the at least one lumen of a said deliveryelement.B7. The interface according to any one of items B1-6, wherein said formis is/are one or more partitions arranged or arrayed in one or acombination of the following:

substantially concentric configurations, each of said partitionsdefining at least a part of a further one of said at least one lumen,whether said partitions define a lumen that extends substantially theentirety of the length, or a partial length, of the total length of adelivery element through which said flow of supplied gas is directed,

a hexagonal or honey-comb type configuration of partitions, whether saidpartitions defines at least a part of a further one of said at least onelumen, or whether said partitions define a lumen that extendssubstantially the entirety of the length, or a partial length, of thetotal length of a delivery element through which said flow of suppliedgas is directed,

a cross-hatch or grid-type arrangement of partitions when viewed as across-section through the gas delivery element, the cross-section beingtaken as a substantially orthogonal plane relative to the direction ofthe flow supplied gas through the gas delivery element,

a plurality of intersecting partitions providing plurality of divisionsor dividing interior walls within at least one of said lumen of saiddelivery element,

a plurality of intersecting partitions providing for a plurality ofseparate gas flow pathways within at least one of said lumen of a saiddelivery element,

one or more partitions are vanes interposed within one or more lumen ofsaid delivery element,

combinations of one or more of the above arrangements or arrays.

B8. The interface according to any one of items B1-7, wherein said formis/are one or more partitions, a partition being a dividing wall orstructure extending through or across a delivery element for gas flowmodification or gas flow re-direction.

B9. The interface according to any one of items B1-8, wherein said formimposes upon the flow of gas through one or more regions of one or moredelivery elements.

B10. The interface according to any one of items B1-9, wherein said formimposes upon the flow of gas through one or more regions of one or moredelivery elements to modify the gas flow by reducing or increasing theReynolds number of the flow of gas, or at least portions of the flow ofgas, through one or more regions of the delivery element.B10. The interface according to any one of items B1-9, wherein said formimposes upon the flow of gas to increase, or decrease, the kineticenergy of a bulk of the gas flow through the delivery element, or alocalised or partial portion of the gas flow through the deliveryelement.B11. The interface according to any one of items B1-10, wherein the formcomprises a helical structure or surface relief extending from, orimposed upon, an interior wall portion of said at least one lumen of oneor more gas delivery elements.B12. The interface according to any one of items B1-11, wherein the formcomprises striations.B13. The interface according to item B12, wherein said striations areoriented along or with or against a flow direction of supplied gasthrough a gas delivery element.B14. The interface according to any one of items B1-13, wherein one ormore of said form(s) is/are located in one or more of:

in a portion or region closer to an outlet from the delivery elementthan an inlet of the supplied gases to the delivery element,

in a portion or region closer to an inlet to the delivery element thanan outlet of the supplied gases from the delivery element,

in a portion or region comparatively more downstream than an upstreamportion or region of a delivery element relative the flow of gassupplied,

in a portion or region comparatively more upstream than a downstreamportion or region of a delivery element relative the flow of gassupplied,

at or substantially adjacent to an outlet (or an end) from the deliveryelement of the supplied gases,

an outlet end of the delivery element.

B15. The interface according to any one of items B1-14, wherein anoutlet end of said delivery element comprises the form as one or aserried of serrated surfaces or undulating shaped or castellated edgeportions.

B16. The interface according to any one of items B1-15, wherein saidform is one or more ribs provided substantially longitudinally alignedwith a gas flow direction through the delivery element, or said one ormore ribs is/are provided substantially laterally (or anotherorientation) substantially relative to a gas flow direction through thedelivery element.B17. The interface according to any one of items B1-16, wherein saidform is of a regular or irregular geometry, when viewed as across-sectional profile or as plan view of a surface of a deliveryelement including such a said form or forms.B18. The interface according to any one of item B1-17, wherein the, orone or more of said, form(s) is/are gas flow directors.B19. The interface according to item B18, wherein a said formstraightens or directs the gas flow into a flow path trajectory or othergas flow characteristic.B20. The interface according to any one of items B1-19, wherein saidform straightens said gas flow or provides or alters said gas flow as ajet or focussed flow of gas through or from said delivery element orthrough or from at least one of said lumen through a delivery element.B21. The interface according to any one of items B1-20, wherein saidform operates as a gas flow multiplier for increasing the flowrate ofprovided to a user, the gas flowrate provided to a user being greaterthan the total gas flowrate delivered through the delivery element of asaid interface.B22. The interface according to any one of items B1-21, wherein saiddelivery element is oriented or angled, such that in-use, said deliveryelement is oriented or angled toward a user's septum.B23. The interface according to any one of items B1-22, wherein a saiddelivery element extends to, or substantially adjacent to, in-use, oneof:

a user's nasal valve

the velopharynx

sufficiently deep into a user's airway or nasal cavity, so s to in-use,avoid or by-pass gas flow being provided in contact with a user'srelatively sensitive nasal epithelia.

B24. The interface according to any one of items B1-23, wherein adelivery element extends in flowpath length, whether automatically inresponse to a characteristic of the supplied gas or by manuallyactuation.

B25. The interface according to any one of items B1-24, wherein saiddelivery element is telescopic.

B26. The interface according to any one of items B1-25, wherein saiddelivery element responds to a change in temperature or a change inhumidity or an electrical current applied thereto.

B27. The interface according to item B26, wherein said response is analteration or change in the geometry or flowpath of a said deliveryelement.

B28. The interface according to any one of items B1-27, wherein anoutlet from a delivery element is shaped or configured to change thevelocity of gas exiting said delivery element.

B29. The interface according to item B28, wherein said velocity (whetheras a bulk property or a localised property of said supplied gas passingthrough or exiting a said delivery element) is increased or decreased.

B30. The interface according to any one of items B1-29, wherein saidform is a flow restrictor.

B31. The interface according to any one of items B1-30, wherein saiddelivery element is of a non-sealing type relative to an airway or anasal cavity or nare into which said delivery element is to be located,optionally such that the nare or airway that said delivery element is tobe located within does not occlude the entire airway or a nare whenin-situ.B32. The interface according to any one of items B1-31, wherein saiddelivery element further comprises one or more structures positioned onan exterior surface of said delivery element, such that, in-use, said asealing of said delivery element with an airway or a nare when in-use,is dissuaded or avoided or prevented.B33. The interface according to any one of items B1-30, wherein saiddelivery element is of a sealing-type, optionally wherein the deliveryelement occludes or seals the airway or nare when in-situ.B34. The interface according to item B33, wherein said delivery elementfurther comprises one or more structures positioned on an exteriorsurface of said delivery element, such that, in-use, said a sealing ofsaid delivery element with an airway or a nare when in-use, isencouraged.B35. The interface according to item B34, wherein said structure(s)comprises one or more inflatable members for encouraging of saidsealing, optionally said member being at least one inflatable cuff.B36. The interface according to item B35, wherein the inflatable memberis inflated to a pressure proportional to the pressure of the suppliedgas or to a pressure correlated to the pressure of the supplied gas.B37. The interface according to item B35 or 36, wherein said inflatablemember is inflated by the supplied gas.B38. The interface according to item B35 or 36, wherein said inflatablemember is inflated by a source of gas other than the supplied gas.B39. The interface according to any one of items B35-38, wherein theinflatable member is manually inflated by a user, or is automaticallyinflated, such as in response to a supplied source of gas.B40. The interface according to any one of items B1-39, wherein saiddelivery element further comprises an accommodation to allow forinsertion of an instrument or tube or conduit or other airway equipment,including a bougie, into a said delivery element to access a user'sairway, such as a nasal cavity or nare.B41. The interface according to any one of items B1-40, wherein saiddelivery element is a nasal prong.B42. The interface according to any one of items B1-41, wherein saidinterface is a nasal cannula including one or a pair of nasal prongs.B43. The interface according to any one of items B1-42, when provided asa nasal cannula comprising one or a pair of nasal prongs as saiddelivery elements, in combination with a further patient interface whenprovided as an oro-nasal or full-face type mask, optionally each of saidpatient interfaces supplied separately with a source of gas to their gasoutlet from respective delivery elements.B44. The interface according to any one of items B1-43, wherein the oran interface or a component associated with a system for providing asupply of gas to said interface, includes a pressure relief mechanism.B45. The interface according to item B44, wherein the pressure reliefmechanism is a valve or other seal configured to open once apre-determined pressure is experienced or sensed within a deliveryelement or at a location along a gas flow path of the gas supplied tothe interface or a said gas delivery element, or said pre-determinedpressure is measured or sensed at another location external to theinterface of the system for providing the supply of gas.

The invention claimed is:
 1. A user interface for providing a flow ofrespiratory gases to a user during a medical procedure comprising: anasal interface comprising a body and a pair of prongs extending fromthe body, the prongs configured to engage nares of the user's nose anddirect high flow respiratory gases into the nares; a mouthpiece adaptedto engage the mouth of the user; wherein the prongs and/or themouthpiece are configured to partially occlude either an oral airway, anasal passage, or both the oral airway and the nasal passage in use;wherein each prong is independently inflatable to create a partial sealwith the nares of the user; and wherein the prongs are configured to beinflatable to create a partial occlusion with the nares of the userduring use while the nasal interface directs high flow respiratory gasesinto the nares, wherein the partial occlusion comprises a gap between anouter surface of each of the prongs and the nares of the user.
 2. Theuser interface according to claim 1 wherein the mouthpiece is configuredto create at least a partial seal with the mouth/oral airway of theuser.
 3. The user interface according to claim 1 wherein the userinterface is adapted to allow a user to selectively create at least apartial occlusion with the nares of the user or with the oralairway/mouth or with both.
 4. The user interface according to claim 1wherein the mouthpiece is shaped to create a seal with the user's mouthor oral airways.
 5. The user interface according to claim 1 wherein themouthpiece is arranged to direct high flow respiratory gases into themouth/oral airways of the user.
 6. The user interface according to claim1, wherein the mouthpiece is inflatable to create at least a partialseal with the mouth of the user.
 7. The user interface according toclaim 6, further comprising a mechanical control mechanism that allowsselective inflation of the prongs, the mouthpiece, or both the prongsand the mouthpiece.
 8. The user interface according to claim 6, whereinthe nasal interface is removably connectable to the mouthpiece.
 9. Theuser interface according to claim 8, wherein the mouthpiece isinflatable when the nasal interface is connected to the mouthpiece. 10.The user interface according to claim 6, wherein the mouthpiececomprises a passage to allow insertion of a medical instrument throughthe mouthpiece, the mouthpiece being shaped to conform to the shape of auser's mouth to create a seal with the mouth.
 11. The user interfaceaccording to claim 10 wherein the passage is selectively openable andcloseable to seal around the medical instrument inserted through themouthpiece.
 12. The user interface according to claim 10, wherein thepassage comprises a passage inflatable seal, the passage inflatable sealbeing adapted to seal around a medical instrument inserted into thepassage.
 13. The user interface according to claim 6, wherein themouthpiece comprises an outer inflatable seal that is adapted to inflateto create a seal with the mouth of the patient user.
 14. The userinterface according to claim 6, further comprising a seal activationmechanism controlling the inflation and deflation of the prongs and/orthe mouthpiece.
 15. The user interface according to claim 6, wherein themouthpiece comprises a valve that can be selectively opened or closedbased on the patient's user's inspiration and expiration.
 16. The userinterface according to claim 15, wherein the mouthpiece comprises apressure line, the pressure line includes a cover slip that is moveablewithin the pressure line, the movement of the cover slip controllingopening and closing of the valve, the cover slip configured to move toopen the valve during inspiration and the cover slip configured to moveto close the valve during expiration.